Colombian rebels from the National Liberation Army (ELN) said on Monday they have captured two men believed to be from Germany, the second time in a month the armed group has seized foreigners.
The ELN, Colombia's second largest guerrilla group, said in a statement the two were seized in Catatumbo, near the border with Venezuela. It identified the two captives as Uwe Breuer and Gunther Otto Breuer.
The ELN said it considered the two "for now" to be intelligence agents because they could not explain why they were in the area, the statement said.
"In the weeks they have been held, they have not been able to justify their presence in the territory, for which reason they are considered, for now, to be intelligence agents and will continue to be investigated," the ELN statement said.
The German Embassy in Bogota was unable to provide further information but said it was investigating.
Two Canadian and two Peruvian gold mining workers were taken by the ELN in northern Colombia last month, as the group steps up pressure on the government in an apparent bid to be included in peace talks with the FARC.
The ELN is not engaged in talks currently underway in Cuba to bring an end to five decades of war with the Revolutionary Armed Forces of Colombia, the country's largest rebel group known as FARC.
The ELN has battled a dozen governments since it was founded in 1964 and is considered a terrorist group by the United States and European Union. Both the ELN and FARC have stepped up attacks on the infrastructure this year and last, hitting oil pipelines and power lines repeatedly.
Inspired by the Cuban revolution and established by radical Catholic priests, the ELN was close to disappearing in the 1970s but has steadily regained power since that time.
ELN chief Nicolas Rodriguez told Reuters last year it is willing to hold unconditional peace talks to end the war, but refuses to end its kidnapping, bomb attacks and extortion of foreign oil and mining companies before negotiations start.
It is believed to have about 3,000 fighters, financed by "war taxes" levied on landowners and oil companies. It has sought peace before, holding talks in Cuba and Venezuela between 2002 and 2007. Experts say there was a lack of will on both sides to agree on a final peace plan.
(Reporting by Helen Murphy; Editing by Sandra Maler and Todd Eastham)